The Cutting Edge - A Spray to Change Your Hardiness Zone?

One of the banes of gardeners worldwide is cold temperatures. We even have zone designations to tell us if our area is too cold for certain kinds of plants to grow in. But what if you could change your hardiness zone without moving and without a greenhouse? This revolutionary idea is actually a breakthrough on the verge of coming on the market - read on for a BIG surprise . . .

Science Tackles Zone Envy?

As a scientist, I am always on the lookout for information relating to innovations or breakthroughs that will make plant growing easier. One problem that has seemed insoluble is local weather that is too cold for the kinds of plants a gardener would like to grow. Not only does a colder climate limit plant choices, but it also limits the length of the growing season. So even if you can grow certain plants, you might not be able to grow them to fruiting maturity. If your gardening goal is to grow produce, this is another limitation that cold places on your activity.

Until recently, the only solutions have been to invest in an expensive greenhouse setup or to move to a more favorable growing zone. But science has advanced a third solution, based on the very physiological principles that enable some plants to be hardier than others. Imagine a product that can be sprayed on your plants a few days before frost, and then imagine sleeping soundly the night of the frost, knowing that the sprayed plants are safe. Finally, imagine waking up the next day and finding that your plants look as good after the frost as they did the day you sprayed them.

Imagination Becomes Reality

Recently I learned of some important work that has been co-developed by Dr. David Francko at the University of Alabama. It seems that this good doctor experimented with several compounds now in use either in foods or in food production. He discovered that a unique combination of five of them together, formulated into a water-based spray and applied to plants, improved the cold tolerance of plants from 2.2 to as much as 9.4 degrees Fahrenheit, depending upon the plant species. For those who live in zones where frost or freeze occurs just enough to prevent the growing of truly tropical plants, this means the difference of one or two hardiness zones! In fact, Francko stated that, when discussing banana plants, the effect of the spray was to change your hardiness zone to one 200 miles south of you! His example was that growers in the Mobile, Alabama area who sprayed their plants with this formulation would get the same effect on their plants in a cold event as someone in Orlando, Florida with the same plants, but who did not spray them. In other words, the hardiness zone of Orlando, Florida would apply to Mobile, Alabama when the plants are sprayed!

Two mechanisms affect how hardy plants are to cold; they are a natural cryoprotectant, or freeze inhibitor (lowers the temperature at which freezing occurs), and a means to prevent or minimize cell damage even in cases where ice crystals do form within the cells. This new product enhances each factor by both lowering the temperature at which damage is first visible and lowering the temperature at which a plant would finally die. An example shown is an unsprayed banana plant showing severe damage after 20 minutes of exposure to freezing, while a sprayed plant still looks fine after three hours of exposure to the same temperature!

I'm Sold; Where Can I Get It?

The product, called "FreezePruf", is marketed by Liquid Fence. September 1, 2009 is the date for release, but you can pre-order before that date. The product does not promise to enable growers in Ohio to leave true tropical plants outdoors all winter, but it will extend your growing season several weeks at each end and reduce the need for other, more expensive, freeze protection methods. And for those who live in a marginal zone just a bit too cold for tropicals, it might just give you the edge to go truly tropical!

This article was originally published March 14, 2009. Please note that the authors of previously published material may not be available for comment.

About LariAnn Garner

LariAnn has been gardening and working with plants since her teenage years growing up in Maryland. Her intense interest in plants led her to college at the University of Florida, where she obtained her Bachelor's degree in Botany and Master of Agriculture in Plant Physiology. In the late 1970s she began hybridizing Alocasias, and that work has expanded to Philodendrons, Anthuriums, and Caladiums as well. She lives in south Florida with her partner and son and is research director at Aroidia Research, her privately funded organization devoted to the study and breeding of new, hardier, and more interesting aroid plants.